title: The sodium channel gene in Tetranychus cinnabarinus (Boisduval): identification and expression analysis of a mutation associated with pyrethroid resistance.
abstract: BACKGROUND
  The carmine spider mite (CSM), Tetranychus cinnabarinus, is the most harmful mite pest of various crops and vegetable plants. Pyrethroid insecticide fenpropathrin has been used to control insects and mites worldwide, but CSM has developed resistance to this compound.
  
  
  RESULTS
  Three synergists together eliminated about 50% resistance against fenpropathrin in the CSM. A point mutation was identified from the sodium channel gene of fenpropathrin-resistant CSM (FeR) by comparing cDNA sequences between FeR and susceptible (S) sodium channel genes, which caused a phenylalanine (F) to isoleucine (I) change at amino acid 1538 position in IIIS6 of the sodium channel and has been proven to confer strong resistance to pyrethroid in other species. The mRNA expression of the sodium channel gene in the FeR and abamectin-resistant strain (AbR), which was included as a control, were both relatively lower than in the S.
  
  
  CONCLUSIONS
  These results demonstrate that a mutation (F1538I) is present in the sodium channel gene in FeR of CSM, likely playing an important role in fenpropathrin resistance in T. cinnabarinus, but that decrease in the abundance of sodium channel did not confer this resistance. The F1538I mutation could be used as a molecular marker for detecting kdr resistance in Arachnida populations.
authors.affiliation: Key Laboratory of Entomology and Pest Control Engineering of Chongqing, South-west University, Chongqing, China.
authors.forename: Ya-ning
authors.initials: YN
authors.lastname: Feng
authors.forename: Shu
authors.initials: S
authors.lastname: Zhao
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Wen-cai
authors.initials: WC
authors.lastname: Lu
authors.forename: Lin
authors.initials: L
authors.lastname: He
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D004252:DNA Mutational Analysis; D018076:DNA, Complementary; D005260:Female; D015870:Gene Expression; D007305:Insecticide Resistance / Q000235:genetics; D007306:Insecticides; D009154:Mutation; D011722:Pyrethrins; D012333:RNA, Messenger / Q000378:metabolism; D015222:Sodium Channels / Q000235:genetics* / Q000378:metabolism; D040102:Tetranychidae / Q000235:genetics* / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D007306:Insecticides; D011722:Pyrethrins; D012333:RNA, Messenger; D015222:Sodium Channels; C044267:fenpropathrin